/Engine/Source/Runtime/Engine/Public/MaterialExpressionIO.h
const [UE::HLSLTree::FExpression](API\Runtime\Engine\HLSLTree\FExpression) * AcquireHLSLExpressionOrConstant ( [FMaterialHLSLGenerator](API\Runtime\Engine\FMaterialHLSLGenerator) & Generator, [UE::HLSLTree::FScope](API\Runtime\Engine\HLSLTree\FScope) & Scope, const [UE::Shader::FValue](API\Runtime\Engine\Shader\FValue) & ConstantValue ) const